Sparging is an art. For all the hype about imported grains, your sparging technique is what will extract the needed maltose solution from your grains. This is probably the second-hardest part of brewing, extracting the maximum sugars from the grain, without ending up with barley soup. Every brewer does it differently, with different equipment. The cheapest sparger you can build yourself, is a cooler box at least three times as big as the volume of grain after grinding. A sieve arrangement of some sort at the bottom, and of course some sort of valve. This can be a stainless-steel dairy-type ball valve with complete dismantling capabilities, or a hosepipe fitting (sterile) and a meter of hosepipe (STERILE) that you can lift above the liquid level inside the sparger…simple tap, costs almost nothing, easy to STERILISE.
Your duty is now to warm water to 64 degrees Celsius. This is very important, and will seriously influence your ability to extract sugars. It will be necessary to measure the temperature of the mash constantly and keep circulating and heating your sparging water to obtain 64degrees in the mash. This is best done in a cooler box as it keeps the mash at temperature. Once you are certain your mash has reached 64°C, close the lid and leave for an hour. Rinse out the sparge liquor into a stainless steel pot. You should now have a large pot of very sweet liquor. Take a long narrow glass or beaker, and cool some wort down to 20 degrees, check it with the hygrometer. It should bob high, much higher than the section marked as BEER START on the hygrometer scale. This first sparge is the best, but a lot more sugar can be rinsed from your mash Heat back up, without burning or boiling over, to 68 degrees, pour back onto mash. From here on it is your choice how hot you will take the sparge, but NEVER BEYOND 74 DEGREES. We do a leisurely three to four hours to complete our sparge. The entire sparging process revolves around ENZYMES. They are activated at 64 degrees, and die at 74 degrees. At every temperature in-between they act and react a bit differently, and by heating the mash in steps, a greater variety of sugars may be extracted.